An illustrated outline filled in with a solid color(s), usually only black, and intended to represent the shape of an object without revealing any other visual details; a similar appearance produced when the object being viewed is situated in relative darkness with brighter lighting behind it; a profile portrait in black, such as a shadow appears to be. [mid 19th c.]

I could see a silhouette of a figure looking out from the window, but I couldn't tell if it was a man or a woman.